— Orbital Sciences Corp. is studying what it would take to launch people aboard its planned Taurus 2 medium-lift rocket, according to a source inside the company.

Dulles, Va.-based Orbital shifted Taurus 2 development into high gear in February after NASA awarded the company $171 million under the Commercial Orbital Transportation Services (COTS) program to demonstrate an ability to ferry cargo to and from the international space station.

Orbital is shooting for a late 2010 demonstration flight of Taurus 2 and its Cygnus space tug, which is designed to carry interchangeable cargo modules.

NASA’s $500 million COTS program is designed to foster development of a commercial capability to deliver cargo and possibly astronaut crews to the space station to supplement government-provided vehicles like the Russian-built Soyuz and Progress capsules. Orbital’s COTS proposal, unlike that of Hawthorne, Calif.-based Space Exploration Technologies – the only other NASA-funded COTS contender – did not include an option for conducting a crewed demonstration flight.

NASA to date has been unenthusiastic about funding crew-carrying demo flights before one or both COTS contenders show that they can safely deliver cargo. However, legislation currently before Congress could force NASA to fund such a flight as a hedge against long-term reliance on Soyuz vehicles for transporting astronauts to and from the station.

An Orbital source told Space News that the company in early July began an internal study intended to identify the costs associated with human-rating the Taurus 2 and modifying the Cygnus system to carry a two-person crew.

The source said the main market Orbital has in mind is space tourism but that a human-rated Taurus 2 also could be used for space station crew rotation flights if demand warrants.

Orbital spokesman Barron Beneski said July 22 that the company generally does not discuss internal studies since they tend to involve proprietary information. “I can’t discuss what’s happening internal to the company on any program …whether it’s COTS, commercial satellites or missile defense.”

Beneski noted, however, that Orbital took a look at what it would take to field a human-rated system when it put together its winning COTS proposal late last year.

“We chose to focus our efforts on cargo and NASA selected us for that,” Beneski said. “But that’s not to say that we haven’t kept our eye on the human side.”

Beneski said that should NASA’s plans “call for a more significant look and examination of what the options are for Capability D, then we will be prepared to discuss our ideas with NASA.”

Capability D is COTS contracting parlance for demonstrating the ability to transport crews to and from the space station.